You can easily read the source code of the game in the linked play.js file.

That enter works may be a bug, as it’s not programmed in specifically. The game subtracts 32 from each non-space character to map it to a keyboard keycode (for letters this happens to transform lowercase into uppercase, and it also happens that the keycodes for letter keys are their uppercase ascii values). The ascii code for ‘-‘ is 45, and the keycode for enter is 13.

To get the ‘?’ you’d have to type the “IME mode change” key. I have no idea how to do that. Anyway, there are no lines after “are you a hacker?”, and I’m not sure what will happen if you somehow get past it. Kill screen maybe?